Polyurethane foam prepared from graft copolymers of vinyl monomers and unsaturated polyols containing alkenyl aryl constituents

ABSTRACT

Graft copolymers of vinyl monomers and unsaturated polyols are described. These copolymers are prepared by the polymerization of an ethylenically unsaturated monomer, or a mixture of such monomers, in a polyol comprising an alkenyl aryl polyol. The alkenyl aryl constituents render the polyols compatible for graft copolymerization with the vinyl monomers. The graft copolymers are shown in polyurethane formulations.

This application is a divisional of co-pending U.S. Application Ser. No.783,354, filed Mar. 31, 1977 now U.S. Pat. No. 4,140,667 issued Feb. 20,1977.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to graft copolymers of ethylenically unsaturatedmonomers and unsaturated polyols containing alkenyl aryl constituents.The invention further relates to the use of these graft copolymers inpolyurethane formulations.

2. Prior Art

A great deal of art has arisen focusing on methods for increasing theoverall molecular weight of polyols without seriously affecting chainlength and attendant fluidity, by incorporating polymeric materials ontothe polyol by grafting. Such graft copolymer polyol dispersions haveproven to be advantageous when used in polyurethane formulations toachieve desirable polyurethane product properties such as enhanced loadbearing and resiliency in foams.

It is known in the art to prepare graft copolymer dispersions from vinylmonomers and polyols and to use these copolymers in the formulation ofurethane polymers. For example, U.S. Pat. No. 3,383,351 to Stambergerteaches that ethylenically unsaturated monomers may be polymerized in apolyol medium. As evidenced by Patton et al in U.S. Pat. No. 3,966,521,graft copolymers could also be formed by reacting vinyl monomers inpolyols containing some degree of unsaturation. Both of these patents,however, fail to show graft copolymers which are prepared from vinylmonomers and alkenyl aryl polyols.

Graft copolymers also are described in U.S. Pat. No. 3,190,925 to Stowewhich are prepared by copolymerizing an ethylenically unsaturatedmonomer with an alkenyl benzyl polyglycol such as: ##STR1## However,these graft copolymers are not prepared from alkenyl aryl polyols, and,hence, do not contain the multiple hydroxyl groups as are required foruse in polyurethane formulations.

SUMMARY OF THE INVENTION

Now, an improved graft copolymer has been developed which can beprepared by reacting ethylenically unsaturated monomer in a polyolcomprising an alkenyl aryl polyol. Presence of the alkenyl arylconstituent on the polyol enhances graft copolymerization reactivitywith unsaturated monomers. The resulting graft copolymers featuremultiple hydroxyl groups and are used in polyurethane formulations.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The graft copolymers of the present invention can be prepared byreacting certain alkenyl aryl polyols with ethylenically unsaturatedmonomers.

The alkenyl aryl polyol reactant can be represented by the generalformula: ##STR2## wherein:

R₄ is straight or branched chain alkenyl of 2 to 10 carbons,

R₂ is lower alkylene of 1-4 carbons, or ##STR3## where u is an integerfrom 0 to 3,

p is an integer from 2-5, and

--O--R₃ --OH_(p)) is a residue of a polyol R₃ (OH)_(p) +1, having anequivalent weight ranging from 250 to 5000,

after removal of one hydroxy hydrogen therefrom.

These alkenyl aryl polyol reactants can be prepared by reacting a polyolwith an alkenyl aryl reactant which contains a second functionalityreactive with a polyol. This second reactive functionality may be suchas an alkyl halide, a carboxylic acid or acid halide group, or an ester.These functionalitites are reactive with a hydroxyl group of a polyol sothat the alkenyl aryl group can be incorporated onto the polyol chain.

The alkenyl aryl reactant can be represented by the general formula:##STR4## wherein:

R₄ is straight or branched chain alkenyl of 2 to 10 carbons,

b is an integer from 0 to 3, and

R₅ is a methyl halide group, a carboxylic acid group, correspondingcarboxylic acid halides, or corresponding carboxylic acid lower alkylesters of 1 to 4 carbons.

The alkenyl aryl compounds which can be used to form the alkenyl arylpolyol include alkenyl aryl carboxylic acids such as alkenyl benzoicacids, alkenyl phenyl acetic acids, alkenyl phenyl propionic acids,alkenyl phenyl butyric acids, and the like, and their functionalderivatives such as their acid halides and esters, which readily can beprepared from the acids by conventional means. Other alkenyl arylcompounds also include alkenyl aryl alkyl halides such as alkenyl benzylhalides, alkenyl phenyl ethyl halides, alkenyl phenyl propyl halides,alkenyl phenyl butyl halides, and the like. The alkenyl segment of thesecompounds includes straight and branched chain alkenyl, such as ethenyl,isopropenyl, propenyl, butenyl, octenyl, decenyl, and the like.Polyethylenic alkenyl groups (dienes, trienes, etc.) are also included,such as butadienyl, pentadienyl, heptatrienyl, decatrienyl, and thelike. Preferred are alkenyl aryl reactants of the formula: ##STR5##wherein R₁ is hydrogen or methyl and b and R₅ are as defined in FormulaII above.

Vinyl aryl alkyl halide, in specific, chloromethyl styrene, isparticularly preferred. The chloromethyl-styrenes can be prepared byvarious known methods, such as are described in U.S. Pat. No. 3,049,503,column 2, lines 55-67.

The relative position of the second reactive functionality on thebenzene ring of the alkenyl aryl compound is not critical to theinvention. The preferred chloromethyl styrene reactants prepared byknown methods commonly are ortho and para mixtures. It is further notedthat one or more other constituents which are innocuous to the reaction,such as alkyl or halo constituents, may also be present at the openpositions of the aromatic ring.

For purposes of simplicity in presentation, the preferred vinyl benzylpolyol reactants have been chosen for detailed discussion below. Theycan be prepared by a method exemplified by the following illustration:##STR6##

As depicted above, the vinyl alkenyl aryl compound having a secondreactive functional alkyl halide group is reacted with the polyethertriol. This ether-forming reaction takes place in the presence of sodiumhydroxide at a temperature of about 50°-150° C. Through nucleophilicsubstitution, the halide ion of the vinyl monomer is replaced to resultin the formation of the vinyl benzyl polyol. The reaction involved isdetailed further in co-pending Ser. No. 783,354, and the entiredisclosure of this application is hereby incorporated in its entirety byreference.

When the second reactive functionality of the alkenyl aryl monomer is acarboxylic acid, acid chloride or ester group, the reaction with thepolyol is an esterification or a transesterification type reaction,proceeding in common fashion, in non-basic media.

The polyol reactant which is used in preparing the alkenyl aryl polyolsof the invention can be any such compound, including mixtures of two ormore such compounds, having 3-6 hydroxyl groups and preferably anaverage equivalent weight from about 250 to about 5000. This includespolyester polyols and polyether polyols. However, the polyether polyolsare generally preferred.

The polyester polyols include the products of reacting polycarboxylicacids with the polyhydric alcohols. Illustrative polycarboxylic acidsinclude, for example, oxalic, malonic, succinic, glutaric, adipic,pimelic, suberic, and azelaic acid and the like. Illustrative polyhydricalcohols include various triols, tetrols, and higher-functionalityalcohols, such as glycerol, trimethylolpropane, pentaerythritol,sorbitol, mixtures thereof and the like.

The polyether polyols, the use of which is preferred herein, includevarious polyoxyalkylene polyols and mixtures thereof. These can beprepared, according to well-known methods, by condensing an alkyleneoxide, or a mixture of alkylene oxides using random or step-wiseaddition, with a polyhydric initiator or mixture of initiators.Illustrative alkylene oxides include ethylene oxide, propylene oxide,butylene oxide, and the halogenated alkylene oxides such astrichlorobutylene oxide and so forth. The most preferred alkylene oxideis propylene oxide or a mixture thereof with ethylene oxide using randomor step-wise oxyalkylation.

The polyhydric initiators used in preparing the polyether polyolreactant can be any such material which has from 3 to 6 activehydrogens. This includes (a) the aliphatic triols such as glycerol,trimethylolpropane, triethylolpropane, trimethylolhexane and the like,(b) higher-functionality alcohols such as sorbitol, pentaerythritol,methyl glucoside, and the like, (c) the polyamines such as tetraethylenediamine and (d) the alkanolamines such as diethanolamine,triethanolamine, and the like.

A preferred group of polyhydric initiators for use in preparing thepolyether polyol reactant is one which comprises aliphatic triols suchas glycerol, trimethylolpropane, and the like.

The alkylene oxide-polyhydric initiator condensation reaction ispreferably carried out in the presence of a catalyst such as KOH as iswell-known in the art. In effecting the reaction, a sufficientproportion of alkylene oxide is used as to provide a final polyolproduct having an average equivalent weight of about 250-5000,preferably about 700-3000, and more preferably about 1000-1500. Thecatalyst is thereafter preferably removed, leaving a polyether polyolwhich is ready for use in preparing the alkenyl aryl polyols of theinvention.

To form the graft copolymers of the present invention, the alkenyl arylpolyols are treated with an ethylenically unsaturated monomer, or amixture of such monomers, usually in the presence of additional polyol,selected from the polyols as defined above. The monomers useful in thecopolymerization process are any polymerizable monomers characterized bythe presence of at least one polymerizable ethylenic unsaturated groupof the type ##STR7##

Representative ethylenically unsaturated monomers which may be employedin the present invention include butadiene, isoprene, 1,4-pentadiene,1,6-hexadiene, 1,7-octadiene, styrene, α-methylstyrene, methylstyrene,2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene,phenylstyrene, cyclohexylstyrene, benzylstyrene, and the like;substituted styrenes such as chlorostyrene, 2,5-dichlorostyrene,bromostyrene, fluorostyrene, trifluoromethylstyrene, iodostyrene,cyanostyrene, nitrostyrene, N,N-dimethylaminostyrene, acetoxylstyrene,methyl 4-vinylbenzoate, phenoxystyrene, p-vinyl diphenyl sulfide,p-vinylphenyl phenyl oxide, and the like; the acrylic and substitutedacrylic monomers such as acrylonitrile, acrylic acid, methacrylic acid,methylacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,methyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate,isopropyl methacrylate, octyl methacrylate, methacrylonitrile, methylα-chloroacrylate, ethyl α-ethoxyacrylate, methyl α-acetaminoacrylate,butyl acrylate, 2-ethylhexylacrylate, phenyl acrylate, phenylmethacrylate, α-chloroacrylonitrile, N,N-dimethylacrylamine,N,N-dibenzylacrylamide, N-butylacrylamide, methacrylyl formamide, andthe like; the vinyl esters, vinyl ethers, vinyl ketones, etc., such asvinyl acetate, vinyl chloroacetate, vinyl alcohol, vinyl butyrate,isopropenyl acetate, vinyl formate, vinyl acrylate, vinyl methacrylate,vinyl methoxy acetate, vinyl benzoate, vinyl iodide, vinyl toluene,vinyl naphthalene, vinyl bromide, vinyl fluoride, vinylidene bromide,1-chloro-1-fluoro-ethylene, vinylidene fluoride, vinyl methyl ether,vinyl ethyl ether, vinyl propyl ethers, vinyl butyl ethers, vinyl2-ethylhexyl ether, vinyl phenyl ether, vinyl 2-methoxyethyl ether,methoxybutadiene, vinyl 2-butoxyethyl ether, 3,4-dihydro-1,2- pyran,2-butoxy-2'-vinyloxy diethyl ether, vinyl 2-ethylmercaptoethyl ether,vinyl methyl ketone, vinyl ethyl ketone, vinyl phosphonates such as bis(β-chloroethyl) vinyl phosphonate, vinyl phenyl ketone, vinyl ethylsulfide, vinyl ethyl sulfone, N-methyl-N-vinyl acetamide,N-vinyl-pyrrolidone, vinyl imidazole, divinyl sulfide, divinylsulfoxide, divinyl sulfone, sodium vinyl sulfonate, methyl vinylsulfonate, N-vinyl pyrrole, and the like; dimethyl fumerate, dimethylmaleate, maleic acid, crotonic acid, fumaric acid, itaconic acid,monomethyl itaconate, t-butylaminoethyl methacrylate, dimethylaminoethylmethacrylate, glycidyl acrylate, allyl alcohol, glycol monoesters ofitaconic acid, dichlorobutadiene, vinyl pyridiene, and the like. Any ofthe known polymerizable monomers can be used and the compounds listedabove are illustrative and not restrictive of the monomers suitable foruse in this invention.

Preferred monomers include styrene, acrylonitrile, vinyl chloride,methyl methacrylate, hydroxy ethyl acrylate, butadiene, isoprene,chloroprene, and the like. Styrene and acrylonitrile are particularlypreferred.

The overall grafting reaction proceeds in a manner as is known in theart, using conventional reaction conditions, reactants, and proportions;the improvement being, however, including an unsaturated polyolcomprising an alkenyl aryl polyol. The copolymerization can becharacterized by the following example, where a vinyl benzyl polyetherpolyol and styrene have been chosen as illustrative reactants forpurposes of presentation simplicity: ##STR8##

During the free radical grafting copolymerization, any suitable freeradical initiator may be used. Illustrative catalysts are the well-knownfree radical type of vinyl polymerization catalysts, for example, theperoxides, persulfates, perborates, percarbonates, azo compounds, etc.,including hydrogen peroxide, dibenzoyl peroxide, acetyl peroxide,benzoyl hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide,lauroyl peroxide, butyryl peroxide, diisopropylbenzene hydroperoxide,cumene hydroperoxide, paramenthane hydroperoxide, diacetyl peroxidedi-α-cumyl peroxide, dipropyl peroxide, diisopropyl peroxide,isopropyl-t-butyl peroxide, butyl-t-butyl peroxide, dilauroyl peroxide,difuroyl peroxide, ditriphenylmethyl peroxide,bis(p-methoxybenzoyl)peroxide, p-monomethoxybenzoyl peroxide, rubreneperoxide, ascaridol, t-butyl peroxybenzoate, diethylperoxyterephthalate, propyl hydroperoxide, isopropyl hydroperoxide,n-butyl hydroperoxide, t-butyl hydroperoxide, cyclohexyl hydroperoixde,trans-Decalin hydroperoxide, α-methylbenzyl hydroperoxide,α-methyl-α-ethyl benzyl hydroperoxide, Tetraline hydroperoxide,triphenylmethyl hydroperoxide, diphenylmethyl hydroperoxide,α-α-azo-2-methyl butyronitrile, α,α-2-methyl heptonitrile,1,1'-azo-1-cyclo-hexane carbonitrile, dimethyl, α,α'-azo-isobutyrate,4,4'-azo-4-cyanopentanoic acid, azo-bis (isobutyronitrile), persuccinicacid, diisopropyl peroxy dicarbonate, and the like; a mixture ofcatalysts may also be used. Azo-bis (isobutyronitrile) is the preferredcatalyst.

The amounts of the respective reactants in the graft copolymerizationreaction determine the extent of copolymerized product present in thefinal graft copolymer dispersion. By varying the reactant proportions, arange of graft copolymerized products can be formed, which, in turn canbe utilized in formulations to produce various polyurethane properties.

The alkenyl aryl polyol reactant may be reacted alone with unsaturatedmonomer, but preferably it is supplemented with additional polyol,selected from the polyol reactants defined previously above. Anyunreacted monomer can readily be stripped from the product byconventional means. The graft copolymer product can be separated fromunreacted polyol by standard means, such as solvent extraction. Thealkenyl aryl polyol preferably is supplemented with additional polyolsuch that the alkenyl aryl polyol constitutes from 1 to 100 percentbased on the weight of total polyol. Using about 40 to 60 percentalkenyl aryl polyol has been found to be most preferred. In forming thealkenyl aryl polyol reactant, it is advantageous to use excess polyolreactant, which preferably is allowed to remain with the product toresult in an alkenyl aryl polyol-unreacted polyol mixture. Anadvantageous graft copolymerization reaction scheme is then to addmonomer, catalyst and the azo-bis ester polyol-unreacted polyol mixtureseparately or combined to a heated reactor containing additionalunreacted polyol in order to produce a graft copolymer of monomer andpolyol dispersed in a polyol medium. Reaction temperatures normallyrange between about 80° to 170° C., preferably from about 90° to 140° C.Increasing viscosity of the reaction mixture indicates progress of thereaction.

The amount of ethylenically unsaturated monomer used in thepolymerization reaction preferably ranges from about 1 to 30 percent,and most preferably from about 3 to 25 percent, based on the weight oftotal polyols.

The concentration of the catalyst can vary from about 1% to about 10%,preferably from about 2% to about 5% by weight based on the weight ofthe monomer.

The graft copolymer dispersions of the present invention areparticularly suited for use in polyurethane formulations, as shown inExamples VI and VII below. The presence of the multiple terminalhydroxyl groups allows the polyurethane forming reaction with organicpolyisocyanates. Modification of the amount of terminal hydroxyl causesvariation of resulting polyurethane products. The amount of branchingand cross-linking is directly dependent on the number of hydroxyl groupsin the original resin. Properties can be varied to form polyurethaneproducts such as elastic fibers, elastomers, or flexible, semi-rigid, orrigid foams.

Although the invention is of utility in the preparation of non-cellularpolyurethanes as well as polyurethane foams, the preparation of foamsaccording to the invention is preferred.

In the preparation of the present polyurethane foams, either of thegeneral forming processes, the "one-shot" or the "prepolymer" processes,may be utilized. Any combination of graft copolymer, additional polyol,organic polyisocyanate, foaming agent, catalyst, and other reactantcapable of forming a polyurethane foam forming reaction mixture can beemployed.

The organic polyisocyanates used in the polyurethane foams of thisinvention include toluene diisocyanate, such as the 80:20 or the 65:35isomer mixture of the 2,4- and 2,6-isomeric forms, ethylenediisocyanate, propylene diisocyanate, methylenebis-(4-phenylisocyanate), 3,3'-bitoluene-4,4-diisocyanate, hexamethylenediisocyanate, naphthalene 1,5-diisocyanate, the polymeric isocyanatessuch as polyphenylene polymethylene isocyanate, and the like, andmixtures thereof. The amount of isocyanate employed in the presentprocess should generally be sufficient to provide at least about 0.7 NCOgroup per hydroxy group in the reaction system, which includes the graftcopolymers, polyols, as well as any additional material and/or foamingagent present. In practice, polyisocyanate is usually used in aproportion to provide no more than about 1.25 NCO groups per eachhydroxy group. A 100 multiple of the ratio of NCO to OH groups in thereaction system is referred to as the "index."

Any suitable foaming agent, or mixture of foaming agents may beemployed. These include inorganic foaming agents, such as water, andorganic foaming agents containing up to seven carbon atoms such as thehalogenated hydrocarbons, and thw low molecular weight alkanes, alkenes,and ethers. Illustrative organic agents includemonofluorotrichloromethane, dichlorofluoromethane,dichlorodifluoromethane, 1,1,2-trichloro-1,2,2,-trifluoroethane,methylene chloride, chloroform, carbon tetrachloride, methane, ethane,ethylene, propylene, hexane, ethyl ether diisopropyl ether, mixturesthereof and the like. Water and the low molecular weight polyhalogenatedalkanes, such as monofluorotrichloromethane and dichlorodifluoromethane,are preferred. The amount of foaming can be varied over a wide range.

The catalyst employed in preparing the foams of the invention may be anyof the catalysts known to be useful for this purpose, including tertiaryamines, organometallic salts, and a mixture of an organo-metallic saltwith one or more tertiary amine, the latter being preferred. Typicaltertiary amines include for example triethylamine, triethylene diamine,trimethylamine, tetramethylene diamine, tetramethylbutane diamine,N-methylmorpholine, N-ethylmorpholine, dimethylpiperazine,trimethylaminoethylpiperazine, dimethylcyclohexylamine, mixtures ofbis(dimethylaminoethylether) and dipropylene glycol such as the 7:3weight ratio mixture which is available commercially under the trademarkNiax A-1, methyldicyclohexylamine, N-cyclohexylmorpholine,dimethylcyclohexylamine, methyldiethanolamine, a mixture ofdimethylcyclohexylamine and 2(3-pentyl)-1-dimethylaminocyclohexane suchas may be purchased commercially under the Trademark Polycat,bis(dimethylaminoethylpropylether), mixtures of triethylene diamine anddipropylene glycol such as the 1:2 and 1:4 weight ratio mixtures whichmay be purchased commercially under the trademarks Dabco 33LV and Dabco8020, respectively, bis(dimethylaminopropylether), and mixtures of thesecatalysts. The preferred tertiary amine catalysts aretriethylenediamine, mixtures of triethylenediamine with dipropyleneglycol, mixtures of bis(dimethylaminoethylether) and dipropylene glycol,dimethylcyclohexylamine alone or as a mixture thereof with2-(3-pentyl)-1-dimethylaminocyclohexane. The teriary amine catalyst isused in a proportion of about 0.1-1.5, and preferably about 0.25-0.75,parts per 100 parts by weight of the total polyol which is employed inpreparing the foam.

Typical organo-metallic salts include for example the salts of tin,titanium, antimony, aluminum, cobalt zinc, bismuth, lead, and cadmium,the tin salts, i.e., stannic and stannous salts, being preferred.Illustratively such salts include the octoates, dilaurates, diacetate,dioctoates, oleates, and neodeconates of these metals, the octoatesbeing preferred. The organometallic salt catalyst is used in aproportion of about 0-0.5, and preferably about 0.05-0.2, parts per 100parts by weight of total polyol which is employed in the preparation ofthe foam.

It is preferred in the preparation of the polyurethane foams of theinvention to employ minor amounts of a conventional surfactant in orderto further improve the cell structure of the polyurethane foam. Typicalof such surfactants are the silicone oils and soaps, and thesiloxane-oxyalkylene block copolymers. U.S. Pat. No. 2,834,748 and T. H.Ferrigno, Rigid Plastic Foams (New York: Reinhold Publishing Corp.,1963), pp. 34-42, discloses various surfactants which are useful forthis purpose. A preferred group of surfactants are the polysiloxanessuch as may be purchased under the trademark "Niax L-5303." Generally,up to two parts by weight of the surfactant are employed per 100 partsof total polyol.

The following examples are provided to further illustrate the invention.All parts and percentages are by weight unless otherwise specified.

PREPARATION OF ALKENYL ARYL POLYOLS Example I Preparation of VinylBenzyl Polyol Ether

3 g. (0.075 moles) NaOH was added to 325 g. (0.072 moles) of a polyethertriol made from glycerin by block addition of propylene oxide capped byethylene oxide to form a polyether triol having >70% primary hydroxylgroups and an average molecular weight of about 4500. The mixture wasstirred under N₂ at 90° to 100° C. for two hours, until all the NaOHdissolved. 6 g. (0.04 moles) of chloromethyl styrene was then added andthe reaction was allowed to continue for two hours at 90° C. The productwas then treated with 16 g. supercel and 16 g. mangesol to remove thesalt and any unreacted NaOH, filtered through Whatman No. 1 filterpaper, and then stripped at 2 mm Hg at 100° C. for one hour to removeany unreacted chloromethyl styrene reactant.

UV and IR analyses indicated the presence of vinyl and benzene moietiesto confirm formation of the vinyl benzyl polyol ether product. The OHnumber was analyzed to be 31.0 mg KOH/g. This is in good agreement withthe theoretical OH number of 31.0 mg KOH/g for the anticipated vinylbenzyl polyol ether product.

EXAMPLE II Preparation of Vinyl Benzyl Polyol Ether

A 3-liter, three neck flask equipped with N₂ inlet, thermometer, feedinlet, and stirrer was charged with 1500 gm. (0.332 moles) of apolyether triol made from glycerol by block addition of propylene oxidecapped with ethylene oxide to form a polyether triol having about 4500molecular weight containing 10% EO as end block. To this was added about28 gm of a 50% solution of sodium hydroxide in water. The mixture waspurged with N₂ under surface for 20 minutes. The flask was then heatedto 110° C. for two hours. The water then was purged out with N₂ and thereactor was cooled to 50° C. 27.7 g. (0.185 moles) of vinyl benzylchloride was then added dropwise. The reaction was allowed to continuefor 41/2 hours. The contents showed the formation of a white solid(likely to be NaCl, a by-product of reaction).

The salt and any unreacted NaOH were removed by clay treatment. 30 gmmicrocell, 30 gm magnesol, and 15 gm celite were added to the flask andmixed at 110° C. for two hours. The material was then filtered hotthrough Whatman NO. 1 filter paper with <5 mm Hg. pressure. A yellow,clear product was obtained, which was stripped to remove unreacted vinylbenzyl chloride. UV indicated the presence of a benzene ring andunsaturation moieties to confirm formation of the vinyl benzyl polyolether product. This material had a hydroxyl number or 33.8 mg KOH/g andunsaturation equal to 0.15 milliequivalent/gm.

PREPARATION OF GRAFT COPOLYMERS Example III

The product of Example I was used to make a graft copolymer with styreneby free radical reaction.

15 g of the product of Example I was mixed with 5 g styrene and 0.4 gABIN (azo-bis-isobutyronitrile). The mixture was stirred at 80°-95° C.for one hour. The product was then stripped to remove any unreactedstyrene. The viscosity of the product was 6400 cps. NMR analysis foraliphatic and aromatic protons showed that the product contained 23%styrene. Gel Permeation Chromatography molecular weight analysisconfirmed copolymer formation.

Example IV

The product of Example I was used to make a graft copolymer with styreneand acrylonitrile by free radical reaction.

24 g. of the product of Example I was added to 16 g. of the polyolreactant used in Example I and this was stirred and heated, under N₂, at100° C. to form a uniform blend. To this was added a mixture of 4.5 g.styrene, 0.5 g. acrylonitrile, and 0.15 g. ABIN, and allowed to reactfor one hour at 80°-95° C. The product was then stripped to remove anyunreacted monomers. The viscosity of the product was found to be 1500cps at 25° C. (about 700 units more than the starting polyol reactant).The graft copolymer product was determined to contain about 11%polyethylenic residues. GPC confirmed copolymer formation. The copolymerproduct was yellow, but non-turbid.

EXAMPLE V

The vinyl benzyl polyol (product of Example II) was used to make acopolymer with styrene as follows:

A 1-liter three neck flask equipped with N₂ inlet, feed inlet, stirrer,thermometer, and reflux condenser was charged with 222 gm of thepolyether triol reactant used in Example II. The flask was heated undera N₂ blanket to 100° C. A "blend" of 1.7 gm azo-bis-iso-butyronitrile,6.0 gm acrylonitrile, 50 gm styrene, and 222 gm of the alkenyl arylpolyol product material from Example II was made. When the flask reached100° C., the above-described blend was fed to the flask at a steady rateof 1.4 gm/min. The feed time was three hours and twenty minutes. At theend of feeding operation, the reaction was allowed to continue for onehour. The material was then stripped at 100° C. and <5 mm Hg vacuum toremove any unreacted monomer. The material balance at the end showedthat 96% of the monomers charged reacted to form graft copolymer.

The final product had a viscosity of 4750 cps (at 25° C.), hydroxylnumber of 33.1 mg KOH/gm. The material is slightly yellow in color andtranslucent.

URETHANE FOAM FORMATION EXAMPLE VI

A cellular flexible urethane foam was made by using the product ofExample V. The general process scheme for making such a foam is widelyknown. The following formulation was used:

    ______________________________________                                                           Parts by Weight                                            ______________________________________                                        Polyether triol.sup.1                                                                              80                                                       Copolymer of Ex. V   20                                                       Diethanol Amine      0.8                                                      Triethylene Diamine.sup.2                                                                          0.4                                                      Surfactant.sup.3     1.3                                                      Water                2.0                                                      Dibutlyl tin dilaurate                                                                             0.1                                                      TDI-80.sup.4 [Index] 109                                                      ______________________________________                                         .sup.1 6500 MW triolprepared from glycerol by base catalyzed block            addition of propylene oxide capped with ethylene oxide such that the          primary hydroxyl content is 68% and the final OH No. is 26 mg KOH/gm.         .sup.2 This is a commercially available product sold under the trademark      "DABCO 33LV." It consists primarily of triethylene diamine (1/3) and          dipropylene glycol (2/3).                                                     .sup.3 This is a commercially available polysiloxane surfactant sold unde     the trademark "NIAX L5303."                                                   .sup.4 This is a mixture of toluene diisocyanate isomers (80/20 mixture o     2,4/2,6isomers).                                                         

The foam processing was good. The gel time was 100 seconds. Followingfoam physicals were obtained:

    ______________________________________                                        Density.sup.1                  2.81                                           ILD.sup.2                                                                     Compression Deflection                                                                             25%       0.28                                                                65%       0.74                                           Sag Factor                     2.68                                           Tensile Strength.sup.3         19.5                                           Elongation.sup.4               163                                            Tear Strength.sup.5            2.1                                            ______________________________________                                         .sup.1 lbs. per cubic foot.                                                   .sup.2 Identation Load Deflection (lbs.) per ASTM D1564-64T Sag Factor, a     measure of the support of cushioning material, is expressed as a ratio of     65% ILD to 25% ILD.                                                           .sup.3 psi per ASTM 156464                                                    .sup.4 percent per ASTM 156464                                                .sup.5 lbs. per linear inch per ASTM 156464                              

URETHANE FOAM FORMULATION EXAMPLE VII

A cellular flexible urethane foam, similar to Example VI was made usingthe following formulation (see Example VI for definitions):

    ______________________________________                                                           Parts by Weight                                            ______________________________________                                        Polyether Triol.sup.1                                                                              80                                                       Copolymer of Ex. V   20                                                       Diethanol amine      0.8                                                      Triethylene Diamine  0.4                                                      Surfactant           1.0                                                      Water                2.0                                                      Dibutyl tin dilaurate                                                                              0.1                                                      TDI-80 [Index]       109                                                      ______________________________________                                         .sup.1 A 4500 MW triolprepared from glycerol by base catalyzed block          addition of propylene oxide capped with ethylene oxide. The primary           hydroxyl content is 55% and the final OH No. is 37 mg KOH/gm.            

The foam processing was good. The gel time was 100 seconds. Followingfoam physicals¹ were obtained:

    ______________________________________                                        Density                        3.08                                           Compression Deflection                                                                             25%       0.25                                                                65%       0.80                                           Sag Factor                     3.19                                           Tensile Strength               17.8                                           Elongation                     97                                             Tear Strength                  1.09                                           ______________________________________                                    

COMPARATIVE EXAMPLES Example VIII Graft Copolymer Control Run

A control run similar to that of Example III was made, using, however,the polyether triol reactant of Example I rather than the styrylpolyether polyol product of Example I. At the end of one hour anon-uniform material containing chunks of white solid was obtained. Thisindicated that in the control run, most of the styrene homopolymerizedto polystyrene with minimal if any copolymerization with the polyethertriol.

Examples IX and X Polyurethane Foam Preparation

Foam formulations were prepared as in Examples VI and VII respectively,using however 100 parts of the polyether triol reactant and none of thegraft copolymer of Example V. In each case, the foam collapsed before itgelled. Successful foam preparation could not be accomplished.

We claim:
 1. In a polyurethane foam prepared from a reaction mixturecomprising an organic polyisocyanate, a foaming agent, and a polyolreactant, the improvement comprising preparing said foam using a polyolreactant comprising a graft copolymer prepared by polymerizing anethylenically unsaturated monomer or a mixture of such monomers in apolyol comprising an alkenyl aryl polyol of the formula: ##STR9##wherein: R₄ represents straight or branched chain alkenyl of 2 to 10carbons;R₂ represents lower alkyl of 1 to 4 carbons, or ##STR10## whereu is an integer from 0 to 3; p is an integer from 2 to 5; and --O--R₃--(OH)_(p)) represents a residue of a polyether or polyester polyol, R₃(OH)_(p+1), wherein R₃ represents a polyether or polyester chain, saidpolyol having an average equivalent weight ranging from about 250 to5000, after removal of one hydroxy hydrogen therefrom.
 2. The foam ofclaim 1 wherein the graft copolymer polyol reactant is prepared bypolymerizing the monomer in a polyol mixture comprising an alkenyl arylpolyol and an additional polyol, R₃ (OH)_(p+1).
 3. The foam of claim 2wherein the graft copolymer polyol is prepared by polymerizing themonomer selected from the group consisting of styrene, acrylonitrile,vinyl chloride, methyl methacrylate, hydroxy ethyl acrylate, butadiene,isoprene, chloroprene, and mixtures thereof, in the polyol mixture of analkenyl aryl polyol and an additional polyol.
 4. The foam of claim 3wherein the graft copolymer polyol is prepared by polymerizing themonomer selected from styrene, acrylonitrile, and mixtures thereof, inthe polyol mixture, in an amount such that the monomer ranges from about1 to 30 percent based on total polyol weight.
 5. The foam of claim 2wherein the graft copolymer polyol is prepared by polymerizing themonomer in a polyol mixture wherein R₃ (OH)_(p+1) is a polyether triol.6. The foam of claim 5 wherein the polyether triol has an averageequivalent weight of about 1000 to
 1500. 7. The foam of claim 2 whereinthe R₄ constituent of the alkenyl aryl polyol is alkenyl containing onecarbon to carbon double bond.
 8. The foam of claim 7 wherein R₄represents --CR₁ ═CH₂ where R₁ is hydrogen or methyl.
 9. The foam ofclaim 8 wherein R₁ is hydrogen.
 10. The foam of claim 8 wherein R₂represents --CH₂ --.
 11. The foam of claim 10 wherein --O--R₃--(OH)_(p)) represents a residue of a polyether polyol.
 12. The foam ofclaim 11 wherein the polyether polyol is a polyether triol.
 13. The foamof claim 12 wherein the polyether triol has an average equivalent weightof about 700 to
 3000. 14. The foam of claim 13 wherein the polyethertriol has an average equivalent weight of about 1000 to
 1500. 15. Thefoam of claim 12 wherein the polyether polyol is the product of reactinga polyhydric initiator with an alkylene oxide or mixture of alkyleneoxides using random or step-wise addition.
 16. The foam of claim 14wherein the polyether triol is the product of reacting a glycerininitiator with alkylene oxide selected from the group consisting ofpropylene oxide, ethylene oxide or mixtures thereof, using random orstep-wise addition.
 17. The foam of claim 12 wherein the monomer isselected from the group consisting of styrene, acrylonitrile, vinylchloride, methyl methacrylate, hydroxy ethyl acrylate, butadiene,isoprene, chloroprene, and mixtures thereof.
 18. The foam of claim 17wherein the monomer is selected from the group consisting of styrene,acrylonitrile, and mixtures thereof.
 19. The foam of claim 18 whereinthe monomer ranges in an amount from about 1 to 30 percent based ontotal polyol weight.